Lightmate is a free iPhone app developed by Luis Laugga that serves as a simple light meter for photographers. The user interface of the app is designed with clarity in mind, making it easy to use and understand.

The app offers two main modes: aperture and shutter priority. This allows photographers to choose the ISO, aperture, or shutter values according to their camera settings. The priority mode automatically changes to aperture or shutter mode when the corresponding value is adjusted.

Lightmate supports both the back and front cameras, giving photographers the flexibility to measure and update exposure values using either camera. To measure the exposure values, users can simply tap anywhere on the camera's preview screen.

In addition to its main features, Lightmate also allows users to customize the default EV scale for aperture, shutter speed, or ISO values. This can be done in the general iOS Settings menu under the "Lightmate" section.

Overall, Lightmate is a handy tool for photographers who need a simple and straightforward light meter app. With its intuitive user interface and customizable settings, it provides the necessary functionality without any unnecessary complexities.